Republicans have denied that any such strategy exists, The Detroit News reported Tuesday. The GOP is threatening to counter by suing the Michigan Messenger, which broke the story, for libel.
The Web site quoted Macomb County Republican Chairman James Carabelli as saying the party planned to use foreclosure lists to challenge voters.
"It is the most ridiculous thing that we've ever seen," said state Republican Party Chairman Saul Anuzis. "I think these guys so worried about how things are going in Michigan that they're trying to distract voters."
For its part, the Web site says it stands by its story.
The lawsuit was filed in U.S. District Court in Detroit.